bolthoff



(No Model.)

3 Sheets$heet 1. H. BOLTHOPF.

STAMP MILL.

Patented Feb. 24, 1885.

. (No Model.) 3 Shets-Sheet 2.

' H. BOLTHOFF.

STAMP MILL. No. 312,956. Patented Feb. 24, 18815.

Wm f WIN 1 (No Model.) s Sheets-Sheet 3.

H. BOLTHOFF.

STAMP MIL No. 312,956. Patented Feb. 24, 1885.

UNITED STATES EEICE.

PATENT HENRY BOLTHOFF, OF DENVER, COLORADO, ASSIGNOR OF 'ONEHALF TOOHARLES F. HENDRIE, OF SAME PLACE.

STAMP-MILL.

SPECIFICATION forming part of Letters Patent No. 312,956, dated February24, 1885.

Application filed April 2 5, 1883. (X model.)

To all whom it may concern.-

Be it known that I, HENRY BOLTHOFF, a

citizen of the United States, residing at Denver, in the county ofArapahoe and State of 5 Colorado, have invented new and usefulImprovements in Stamp-Mills, of which the following is a specification.

The invention relates to mills for crushing ore, &c.; and the object ofmy improvement is to crush the ore in such manner as to greatly increasethe crushing and discharging capacity of the mortar. This I effect bymeans of an oscillating mortar adapted to bring the, material to becrushed into contact with stamps suspended above, instead of, as heretofore, using pounding stamps with a stationary mortar.

The construction of mill embodying this invention is hereinafterparticularly described and claimed, and is illustrated in theaccompanying drawings,to which referenceis made, and in which T Figure 1represents a vertical longitudinal sectional elevation on line Y Z ofFig. 3 of a stamp-mill showing my improved oscillating mortar at rest.vation showing the bearings of the oscillating mortar and thepitman-connection for operating it; and Fig. 3 is a top view of themortar taken on line \V X of Fig. 1.

The oscillating mortar G, divided into two compartments, S S, isoscillated, as will be presently described, upon a shaft, H, (ortrunnions,) having its bearings in boxes a a of the bed-plates L, inextensions G thereof, said boxes resting on rubber or elastic seats orcushions C, Fig. 1, to prevent jarring said shaft H and the parts whichoscillate the mortar, as will hereinafter be better understood.

Each compartment S is provided with dies F F, as in the commonstamp-mills, and replaceable when worn. The stampsas many as may bedesired-are suspended in a frame above the dies by means of collars BB,rest- 7 ing on rubber or elasticcushions C G on the girts P P of theframe, said collars being adjustable on the stamp-stems A A to permitupward or downward adjustment of the stamps for increasing ordiminishing the force of the blow upon the material to be crushed, and

Fig. 2 is an end sectional eleeach stamp-head 1) having replaceableshoes E, as usual.

Each compartment of the mortar is provided with a screen, N, in a frameon the inside, through which the crushed material is discharged, saidscreen-frames being fastened by wedges Q, Q, so as to be easily removedfor re pairs or exchange. Below these screens N N aprons O O, of wood ormetal, are introduced between the sides of the mortar, over which apronsthe crushed material or pulp may pass to bins or spouts below, saidaprons also serving to protect the workingjoint of the connecting-rod,which oscillates the mortar, from dust or grit.

The sides of the mortar G (see Fig. 2) are extended down to receive thepin or shaft I, which, by means of its connection with therevolvingcrank-K by the connecting-rod J, gives the oscillating motionto the mortar, the

'said crank K receiving its motion from a pul ley, R, and belt, or bydirect connection with the pitman of an engine, as may be desired. Thebed-plate supporting the mortar has upward extensions L L to receiveboxes b b for 7 5 the crank-shaft, and has also sockets L L to receivethe uprights posts U U of the stamp frame, or the posts may be securedthereto in any suitable manner.

The ore or material to be crushed is fed through a hopper or ore-feeder,by which it is distributed equally to each compartment of the mortar. Asmany stamps and dies as are desired may be used. The material is crushedby reason of the oscillation of the mortar 8 5 bringing it in contactwith the heavy stamps suspended above, which latter are thereby forcedupward and drop down again into the mortar, the stamps above onecompartment rising as that compartment rises, while those 0 above theother fall, the fall being arrested, as before described, by the collarsupon the stems meeting the cushioned girts, and at every stroke theoscillation of the mortar distributes the material to be crushed, sothatevery por- 5 tion of the mortars contents receives the poundingaction.

For amalgamating gold ores copper plates may be put inside thecompartments S S and upon the aprons O O.

It will be understood that the'pulverization of the material in themortars is effected by the force of the blow of the rocking mortaragainst the suspended stamps, and that the latter are suspended, asdescribed, in order that they may form yielding abutments to receivetheimpact of thestroke or rocking movement of the mortar. The mortar iscentrally mounted upon the shaft H, so as to give a full rockingmovement of the mortar against the stamps, and the pitman-connectiontherewith is preferably at a point centrally below the bottom of themortar. The adjustment of the stamps is made to suit the stroke of themortar. The ore will be fed into the mortar through a hopper havingtwospouts, one into each compartment. This will be fastened inside theframe and feed ore each way into the mortars. A balance-wheel, T, ismounted tipon the crank-shaft.

Referring to the object of my invention to greatly increase the crushingand discharging capacity'of the mortar, it will be seen by an inspectionof Fig. 1 of the drawings that the oscillation of the mortar and itssudden arrest throws the reduced stuff out to one side of a line'drawnthrough the stamp during the reducing operation, and thereby allows thesolid matter to be always returned by the sudden return throw of themortar beneath the stamp.

- In this operation the discharge of the finer material is automatic,and is caused by giving the mortar an upward throw in the arc of acircle, and suddenly arresting said upward throw at the limit of itsmovement, thus causing the finer material to be thrown away from thecenter of themortar and the coarser material to be returned in positionbeneath the reducing-stamp. By this construction the discharge iseffected at intervals by the upward throw of the mortar and during thereducing-blow, While the return of the coarser material is also effectedat intervals by the return throw of the mortar, and in this way theoperation of discharging is due entirely to the sudden arrest andstoppage of the movement of the mortar, while the operation of placingthe coarser material in position to receive the blow of the stamp is dueentirely to'the equally sudden return movement of the mortar from thepoint' of arrest.

As shown, I have placed the discharge-openings at the inner sides of themortar, near the center of oscillation, to get a better discharge of thefiner material, as the oscillation of the mortar will throw the materialfromthe centers of the reducing-chambers toward the inner sides thereof,and from the inner sides back to the centers at intervals andin'succession, thereby keeping the same in intervals of agitation to andfrom the screens and stamps.

The invention embraced in the'methodor process above set forth ofautomatically discharging the reduced material from the mortar duringthe reducing operation is not claimed herein, as such invention may bepracticed by a different type of stamp-mill, and forms the subject of aseparate and distinct application for a patent filed by me December 19,1884, Serial No. 150,751. I

I claim 1. In a stamp-mill, an oscillatingor vibrating mortar,incombination with suitable means for operating it, and. a suitable stampor stamps, substantially as and for the purpose described. I

2. In a stamp-mill, the combination, with suspended stamps, of amortaradapted to be oscillated to bring its dies upward against the materialbetween them and the shoes of said stamps, substantially as and for thepurpose set forth.

3. In a stamp-mill, the combination, with the suspended stamps A D E anda mortar, G, having two compartments, S S, provided with dies F, screensN N, and dischargingaprons O O, of the shaft H, the pin or shaft I,connecting rod J, and crank K, substantially as and for the purpose setforth. v I

4. An oscillating mortar for stamp-mills, constructed of twocompartments, S S, the screens N N, and the discharge-apronsO O,substantially as and for the purpose set forth.

5. In astamp-mill, the combination,with the frame and an oscillatingmortar, of thestamps provided with collars B, and interposed cushions,O, upon the girt of said frame, substantially as and for the purposedescribed.

6. Inastamp-mill, the combination, with the frame and an oscillatingmortar, of the stamps provided with adjustable collars B B, andinterposed cushions O 0 upon the girt of said frame, substantially asand for the purpose'described.

7. In a stamp-mill, the combination, with an oscillating mortar and thestamps, of the shaft H, boxes at a, the interposed cushions C C, and thebed-plate extension G, substantially as and for the purpose set forth.

8. In combination with a mortar having a discharge-opening, a stamp, andmechanism for enabling the mortar to be oscillated curvilinearly,whereby the reduced stuff is passed to one side of the mortar forautomatic delivery during the reducing operation.

9. In combination with a mortar having a screened discharge, the stamp,and'mechanism for enabling the mortar to be operated to pass the reducedstuff to the said screened opening for discharge from the mortar duringthe reducing operation.

' 1O. A curvilinearly-reciprocating mortar,

312,956 I r s bination with a stamp or stamps operating Within saidoompaltments at one side of said discharge-opening, andpower-connections for I 5 positively operating said mortar,substantially as set forth.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing Witreceiving-apron for the reception and delivery of thecontents of the mortar as discharged therefrom.

13. I11 a stamp-mill, the combination of an oscillating or vibratingmortar, and a stamp or stamps, with independent powerconnec- I tions forpositively operating said mortar, substantially as described. nesses.

14. In a sta1np-1nill, a vertically-oscillating HENRY BOLTHOFF. mortarhaving a pounding-compartment at Witnesses: each side of itspivot-bearings, each conipart- E. P. WRIGHT,

J. W. COOLIDGE.

ment having aside discharge-opening, in com-

